mate-media 1.23.0 release

Changes since the last release: v1.22.1...v1.23.0

mate-media 1.23.0

sync with transifex
add widget name volume-applet to panel-applet
enable/disable StatusIcon applet in XDG dir
Allow disabling either statusicon or panelapplet
edit desktop file for GtkStatusIcon applet
Re-enable old GtkStatusIcon
Enable a mute menuitem for the output
Ensure volume slider is always perpendicular to the panel
Ensure volume icon is always correctly scaled
Convert GtkStatusIcon to real applet